The research proposal focuses on our finding of a growth hormone releasing hormone-like substance (GHRH-LI) in testis and placenta. We have identified GHRH-LI in rat testis and placenta by two distinct, complementary methods: by an enzyme-linked immunosorbent assay (ELISA), we detected GHRH-LI peptide and by nucleic acid hybridization techniques, we detected GHRH-LI mRNA. Northern gel analyses revealed that the GHRH-LI mRNA species in testis is of significantly larger size than the GHRH message in placenta and hypothalamus. Recently, Western gel analyses also demonstrated that testicular GHRH-LI peptide is larger than peptide detected from either hypothalamus or placenta. During the next five years, we plan to further characterize GHRH-LI in testis and placenta by sequencing and localizing both the peptide and the mRNA. Furthermore, through the studies proposed in this application, we hope to define a physiologic function for GHRH-LI in both placenta and testis.